Control system.



K. A. SIMMON.

CONTROL SYSTEM.

APPLICATION FILED DEC. 4. 1913.

1 ,255,475. Patented Feb. 5, 1918.

2 SHEETS-SHEET I.

Trvlhy R/ R2. R5.

INVENTOR ATTORNEY K. A. SIMMON.

CONTROL SYSTEM.

APPLICATION FILED DEC. 4. 1913.

1 255,475. Patented Feb. 5, 1918..

2 SHEETS-SHEET 2.

ITNESSES:

Wig/3 ATTORNEY UNITED sTA'rns nr orrro.

KARL A. SIMMON, OF WILKINSBURG, PENNSYLVANIA ASSIGNOB, TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CQBPORATION OF PENNSYLVANIA.

CONTROL srs'rnin.

. Specification of Letters Patent.

Application filed December 4, 1913. Serial No. 804,703.

To all whom it may concern:

Be it known that I, KARL A. SIMMoN, acitizen of the United States, and a resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Control Systems, of which the following is a specification.

My invention relates to systems of control for electric motors and it has special reference to protective means for avoiding the effects of abnormal conditions in certain of the control apparatus.

The object of my invention is to provide means of the above-indicated character which shall be simple and inexpensive in construction, capable of ready installation and renewal, and reliable and rapidly effective in operation, whereby certain operating difliculties heretofore encountered may be avoided.

More or less trouble has been experienced in the prior motor control art in the matter of the breaking of field winding conductors or leads employed in connection with the familiar drum type field change over switches, which are used quite extensively, particularly in railway control systems, as is well known to those versed in modern railway practice. Such breaking of a main circuit lead naturally has very often occasioned considerable damage, which not only temporarily disabled the car but necessitated extensive repairs.

According to my present invention, I propose to employ a protective scheme which, while not directed toward the prevention of the breakage referred to, will, however, immediately render the damaged circuit inoperative and prevent further injury to the apparatus, and, at the same time, will allow of subsequent operation of the control system, with the damaged circuit omitted. \Vith these ends in view, I provide, according to one modification of my invention, one or more fusible members'disposed operatively adjacent to, and preferably directly over, the cooperating stationary and movable contact members of the drum type field change-over switch. In case abnormal electrical relations exist between or near the cooperating members, such, for instance, as excessive arcing occasioned by a broken field lead, the fusible members are immediately ruptured, thereby breaking the control circuit for actuating the main line switches and subsequently, if desired, breaking the circuit of the actuating means for the field change-over switch, by means of electrical interlocking connections of a familiar type. In this manner, the main motor circuits are completely deenergized and arcing is stopped. In order to render the system again operative without necessitating the renewal of fuses, I provide a double-pole double-throw switch, by means of which, when thrown to what may be termed the emergency position, the fuseholder and the control coil of the fieldchanging switch are eliminated from the circuit and a new control circuit is established, whereby the line switches may again be energized upon the usual movement of the master controller.

As a modification of my invention, I prd vide a switch of the relay type having its actuating coil connected across the field magnet winding of the motor and having its cooperating stationary and movable contact members so arranged that an operation similar to that just recited is carried out automatically.

In the accompanying drawing, Figure 1 is a diagrammatic-view of a control system embodying my invention; Fig. 2 is a diagrammatical view of a modification of the invention; Fig. 3 is an enlarged View taken on the line IIIIII of Fig. i; Fig. 4 is a partial view in elevation of my fieldchangeover switch; and Fig. 5 is a view'in elevation, with parts broken away, of the fuse and the holding device therefor.

Referring to the drawing, the system here shown comprises a plurality of motors having armatures 1 and 2, and field magnet windings 3 and 4, respectively; a plurality of main circuit resistor sections, R R and R a plurality of electrically-operated switches of a well known type for making the various motor-circuit connections; field change-over switches 5 and 6, respectively associated with the field magnet windings; a plurality of operating magnet coils for the switches; a master controller MC that is connected to a source of energy through a control resistor 7 for energizing the magnet coils, and is adapted to assume a plurality Patented rat. 5, i918.

of operating positions a, b and c; and my protective system 8, associated with each of the field-change-over switches 5 and 6.

It should be understood that, whereas, for convenience and clearness in illustration and description, I have shown my invention as incorporated in a simple and familiar control system, the invention is not so restricted in application, but may be readily installed and satisfactorily operated in practically any apparatus embodying cooperating stationary and movable contact members.

Inasmuch as the operation of the greater part of the familiar control system with which my invention is associated is not relevant thereto, it is not deemed necessary to describe the complete systermand only so much will be set forth as is requisite to a clear understanding of the operation of the invention.

The field change-over switches 5 and 6 are shown as being-of the familiar drum type,

and are severally adapted to assume two positions, thefull field position, to which the switch may, if desired, be biased in any suitable manner, as by a spring 9*, and the normal field position to which the switch may be actuated by means of a magnet coil 9. As is well known, the change from the full field to normal field is usually made after the motors are disposed in full series or parallel relation or in both, the change serving to produce a higher motor speed.

The protective system 8 of Fig. 1 comprises one or more fuses 10 of a suitable type that are disposed operatively adjacent to,

and preferably directly over, the contact fingers of each field change-over switch, and are connected through a double-pole, doublethrow switch 11, as hereinafter described.

Assuming the master controller MC to be moved into its position a, a control circuit is established from the positive side of a source of energy, as a trolley, through a portion of the control resistor 7 and the master controller MC, a conductor 12, one blade 12 of the double-pole switch 11, the fuses 10, a conductor 13, the coil of a line switch LS anda conductor 14, back to the control resistor, and thence to the negative side of the source of energy, or ground.

The line witch LS is thereby closed, and a main circuit is established from the trolley, through the switch LS, the coil of a limit switch or throttle L, the resistor sections -R R and R the armature 1 and corresponding full field winding 3 and the other armature and full field winding to ground.

If the master controller is moved to its position b, a circuit i successively established to the coils of the switches that are adapted to severally short-circuit the resistance sections, being controlled by the limit switch L. This operation is familiar and will not be recited here. The motors are thus disposed in full series across the line.

When the maste controller is moved to its position a, a circuit is established through a conductor 15, the actuating coil 9 of the field change-over switches 5 and 6, a second blade of the double-throw switch 11, and a conductor is to the negative control conductor 14. The field change-over switches are thus actuated to their normal field position to produce a higher motor speed.

Since the field change-over switches carry the full motor current, it will be appreciated that, upon the rupture of a field lead that is attached to the switches, the abnormal arcing produced might easily occasion considerable damage. In such a case, however, the fuses 10, which are disposed closely adjacent to the contact fingers'of the switches, are immediately ruptured, thereby opening the control circuit of the line switch LS and opening the switch, whereupon the resistor short circuiting switches will also drop out,

by reason of the familiar interlocking of theircontrolv circuit with the switch L To, render the system again operative, the double-pole, double-throw switch 11, is thrown to its emergency position, whereby the actuating coil 9 of the field change-over switches and the localcircuit of the fuses 10 are dead-ended on switch aws l6 and 17,

respectively. A new connection is made through the blade 12 of the switch 11 from the conductor 12 directly to the conductor 13, thus roviding a circuit for the energization of tie coil of the line switch LS. The actuating coil 9 cannot be energized, even upon movement of the master-controller to its position 0. Consequently, the field change-over switches will not be actuated and the arcing referred to above will not reoccur.

Reference may now be had to'Fig. 2, in which a modification of my invention is shown. A switch 18 of the relay type has a plurality of actuating coils 19 and 20 severally connected across the field windings of the motors. Assuming the switch to 00- cupy. the position shown, a movable contact member 21 bridges a pair of stationary contact fingers 22, which are parallel-circuited by an interlocking contact member marked R out, which is adapted to assume its in position when the switch R, which is connected across the resistor section It, occupies its out position. The parallel circuit is connected through a conductor 23 and a contact finger 24 having association with a contact-carrying member 25 that is movable with the relay, to the conductor 13. The conductor 12 is connected through a contact member 26 of the contact-carrying member 25 to the other end of the parallel circuit referred to above. The coil 9 of the field change-over switch is connected to the conductor 14" through a second contact member 27 that is disposed on the member 25. In the position just described, it will be noted that the energization of the coil of the line switch LS is dependent upon the bridging of the contact fingers 22 by the contact member 21.

Assuming a rupture of a field lead, so that either field magnet windin becomes wholly or partially deenergized, the relay '18 will drop to its lower position, thereby dead-end ing the actuating coil 9 and the above mentioned parallel circuit, and breaking the bridging contact of the member 21 to open the line switch LS. A circuit is automatically established, however, between the conductors 12 and 13 by means of the contact member 26, thus permitting subsequent operation of the main system. The contact member R out is employed to assure re liable operation of the line switch LS at starting, although the control circuit of the switch is temporarily completed through the contact member 26.

' Referring now to Figs. 3, 4 and 5, which show the preferred construction of various arts of my field change-over switch, a rum 28, that is rotatable in suitable bearings, (not shown) carries the movable contact members, of the switches 5 and 6, and a plurality of stationary contact fingers 29 of any suitable construction are secured to an insulating finger-base support 30 to cooperate with the movable contact members, the support being suitably attached to a base, partially shown at 31. A plurality of terminal members 32 for conductors 33 that are associated with the field magnet windings, as shown in Fig. 1, are severally electrically connected to the fingers 29.

Secured to the finger-base support at opposite ends thereof are a plurality of supportin conducting arms 34 to the lower ends 0 which the control conductors leading to the fuse are severally connected by suitable terminal members 35, and to the upper ends of which suitable spring clips 36 are severally attached. a An insulating fuse tube 37 for the fuse 10 is provided with end terminal sleeves 38 to respectively conductively enga e the clips, and has a plurality of side openings 39 through which exposed portions 40 of the fuse severally project. These exposed portions are preferably located in the center and near each end of the fuse tube, as shown in Fig. 5, such an arrangement being considered to give, in the best manner, the requisite protection from any arcing caused by rupture of the adjacent field conductors; but, of course, other arrangements may be used, if desired. Suitable spacing members, as rings 41, are preferably disposed around the tube at each opening 39 to maintain the fuse in its proper exposed position. It will be understood thatmy invention is not restricted to the circuit connections and arrangement of parts herein set forth, and I desire that only such limitations shall be imposed as are indicated in the appended claims.

I claim as my invention:

1. In an electric circuit, the combination with a plurality of motor field-winding sections, a plurality of cooperating relatively movable contact members in circuit with said field-winding sections and means for actuating said movable members to govern said field-winding sections, of means dependent upon abnormal electrical conditions of certain of said contact members for rendering certain of said actuating means inoperative.

2. In an electric circuit, the combination with a plurality of cotiperating relativelymovable contact members and means for actuating said movable members, of means 3. In an electric circuit, the combination.

with a plurality of cooperating relatively movable contact members and means for actuating said movable members, of means dependent upon abnormal arcing conditions between certain of said members for rendering certain of said actuating means temporarily inoperative, and switching means for subsequently rendering the greater portion of said actuating means operative.-

4. In an electric circuit, the combination with a plurality of coiiperating stationary and movable contact members, of electric means for actuating said movable members, means dependent upon abnormal arcing conditions between certain of said members for interrupting the circuit of certain of said actuating means, and switching means for subsequently restoring said actuating means to operativeness with respect to all but said mutually arcing members.

5. In an electric circuit, the combination with a dynamo-electric machine provided with a field winding having a plurality of operative sections and a controlling apparatus for said motor embodying switching means for severally inserting in circuit one or more of said sections, of electro-magnetic means for actuating said switching means, fusible means dependent upon abnormal arcing conditions in said switching means for rupturing said fusible means to break the circuit of said actuating means, and a switch for subsequently reconnecting I having a, plurality of operative sections and a plurality of motor-operating switching means, of associated switching means for normally inserting in circuit all of said sections, a control circuit embodying a plurality of electro-magnetic means for actuating I said first switching means, electric means included in said control circuit for actuating said second switching means to include a smaller number of said sections, a fusible member disposed operatively adjacent to said second switching means and dependent upon abnormal arcing conditions therein for rupturing to break the circuit of said electrio means, and a multi-throw switch having one blade normally disposed in the circuit of said fusible member and adapted, upon actuation to another position, to reconnect said control circuit to omit said electric means.

7. The combination with a series of cooperating stationary and movable contact members, of a fusible member disposed in proximity thereto, and means for making electrical connections to said fusible member.

8. The combination with cooperating stationary and movable contact members and main circuit conductors severally connected to said stationary members, of a fusible member disposed in operative proximity to said contact members and to said conductors, said fusible member to be fused in case of excessive arcing between said contact members and said conductors, and means for making auxiliary circuit connections to said fusible member.

9. The combination with a; series of cooperating stationary and movable contact members, of a supporting member for said stationary members, a fusible member and a holdingv member therefor disposed in operative proximity to each of said contact members, and means associated with said supporting member for making circuit connections to said fusible member and for positioning said holding member.

10. The combination with cooperating stationary and movable contact members, of

a supporting member for said stationary members, a fusible member, a holding member therefor having an opening through which said fusible member extends in operative proximity to said contact members, and means secured to said supporting member for making circuit connections to said fusible member and for detachably positioning said holding member.

nee-rears ll. ll he combination with a movable con tact member, a cooperating stationary contact member and a main circuit conductor connected thereto, of a support for said stationary member, a fusible member, a tubularholder therefor having an opening through which a portion of said fusible member extends in operative proximity to said contact members and to said main conductor, a plurality of terminal members for said fusible member secured to the ends of said holder, resilient means for detachably holding said terminal members, and a plurality of arms severally secured to said sup port and to said resilient means for making auxiliary electrical connections to said fus1 ble member.

12. In. a protective device for electric circuits, the combination with a tubular holder having a plurality of openings intermediate its ends, of a fusible member disposed within said holder and having a plurality of portions severally extending through said openings, means mounted on the holder for maintaining said portions in their exposed positions and a plurality of terminal members for said fusible member secured to the ends of said holder.

'13. In an electric circuit, the combination with a controller drum and a plurality of stationary contact lingers cooperating therewith, of a fusible member disposed adjacent to said contact fingers and adapted to be fused in case of abnormal arcing between said drum and the contact fingers.

14. In an electric circuit, the combination with a series ofmovable contact members and a series of stationary contact members cooperating therewith, of an auxiliary electric circuit comprising a fusible member, said fusible member being disposed adjacent to said contact members and adapted to break said auxiliary circuit in case of abnormal arcing between said contact members.

15. In an electric circuit, the combination with a series of movable contact members and a series of stationary contact members coijperating therewith, of a tubular holder having openings adjacent to said contact members, a fusible member disposed within said holder and having a plurality of portions severally extending through said openings, said fusible member being fused in case of abnormal arcingbetween said contact members.

In testimony whereof, I have hereunto subscribed my name this 25th day of Nov.,

KA i. SIMMON.

Witnesses:

LYNN RILEY, B. B. linens. 

